Digital-signal-processor based multirate control of a two-link flexible-joint robot

Concurrent with the development of multirate strategies, there have been increasing applications of digital signal processors (DSPs) in high-speed control. This paper presents the design and implementation of a multirate PD controller for a two-link flexible-joint robot. The controller was implemented using the TI DSP TMS320C30 evaluation module. Two multirate algorithms, namely multirate output PD controller and multirate input PD controller, were designed and implemented. The multirate controllers are shown to be superior to the conventional single-rate PD controller. Comparison is made in terms of maximum overshoot, rise time and steady-state error of the closed-loop system.